/Engine/Source/Runtime/RHI/Public/GPUDefragAllocator.h
Cancels the specified reallocation request. Note that the allocator doesn't keep track of requests after it's been completed, so the user must provide the current base address. This may not match any of the addresses in the (old) request since the memory may have been relocated since then.
void CancelAsyncReallocation ( [FAsyncReallocationRequest](API\Runtime\RHI\FAsyncReallocationRequest) * Request, const void * CurrentBaseAddress )